Lock opening pliers type key



July 2, 1968 F. P. FINCK, JR 3,390,561

LOCK OPENING PLERS TYPE KEY Filed March 30, 1965 afln u .i @nml M, uw www w,- FIII/lll [hl s l,lll/1111111111;lllll'" n l I i t" .ln 5,1

s i INVENTOR. i w Mm@ 0'@ Q BY 1 1% TT ORNE Y United States Patent O 3,390,561 LOCK OPENING PLIERS TYPE KEY Frederick P. Finck, Jr., Fairfield, Conn., assgnor, by mesue assignments, to The Ruleta Company, Inc., Bridgeport, Conn., a corporation of New York Filed Mar. 30, 1965, Ser. No. 443,787 6 Claims. (Cl. 70-395) ABSTRACT F THE DISCLOSURE Pliers type key for more easily opening tamper foiling locks of the telescopic type commercially termed plunger or draw locks commonly used to prevent or limit the unauthorized separation or relative displacement of parts as do padlocks.

Bref summary of the invention This invention relates to keys for locks of the telescopic type commercially termed plunger or draw locks whose body comprises two axially separable, hollow, cylindrical telescoping parts in the hollow of which there is contained all of the mechanism of the lock including the bolt and the strike or equivalents thereof. An early form of such type of lock is disclosed in expired U.S. Patent No. 1,923,- 025 and has been manufactured by the assignee of the present application. Such locks may be used in place of padlocks and unlike padlocks have no easily severed, slender yoke hooking through parts of a device to be locked together.

The interior mechanism of telescopic locks commonly includes a plunger that is axially slidable in one of the hollow body members and which by shifting in one axial direction causes balls, or other forms of bolts, to project laterally into locking engagement with an internal shoulder of other form of strike carried by the other body member. By shifting in the opposite axial direction the plunger permits the balls to retract so that the two parts of the lock body can be separated to free the part or parts that were fastened together, such as the body and rotary handle of a gas valve.

Such plunger type locks are more tamper proof than ordinary padlocks and have more compact and rugged body parts that can be hardened so that they wiil not yield to hammering or sawing like ordinary padlocks.

In such locks it has been proposed to effect the axial sliding `of the bolt governing plunger by means of a key element that can be inserted through a restricted opening in one end of the lock into engagement with a hollow in the plunger. To provide maximum protection against tampering, the nature of the engagement of the key with the plunger needs be such that the plunger has no reachable nitches, shoulders, apertures or the like that could be hooked onto by such make shifts as bent wires or other ordinary expedients or tools. Preferable the engagement of key and plunger shall be solely frictional. Forms of frictional engagement between key and plunger have formerly been proposed but have lacked sufficient clinging force to enable the key to overcome a plunger biasing spring of desirably strong tension, such as will produce reliable action of the locking and unlocking mechanism.

An object of the present invention is to provide a draw key for operating a telescopic type of lock that is capable of gripping the bolt governing plunger with much more powerful frictional cling thanfor instance in the lock and key construction proposed in U.S. Patent No. 3,033,016.

Another object is to provide such more powerful clinging action of the key by means of a mechanism that requires the exertion of but very little force by the hand of the operator.

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Another object is to increase the forcefulness of the clinging of the key to the plunger of the lock by aring the entire perimeter of the inserted end of the key in a complete circle of lateral directions rather than by spreading the inserted end of the key in only a single line or direction, whereby to increase the area of effective, friction producing contact between key and plunger.

Another object is to provide the key with an operating handle which extends mainly in Ia direction transverse to the axis of the inserted portion of the key, termed a pistol grip handle.

Another object is to provide the key with at least two operating handles disposed for relative swinging movement like the handles of pliers, or of such size as to be squeezed toward each other by the palm of the operators hand.

Another object is to provide the key with as many as three, plier type handles which are relatively swingable in selective pairs-in one case for spreading the inserted end of the key to make it cling to the plunger and in another case for exerting advantageous leverage for enabling the key to pull forcefully in an outward direction on the plunger of the lock so as to permit unlocking while the hand of the user maintains the forceful frictional cling of the key to the plunger aforesaid.

These and other objects of the invention will become clear in greater detail from the following description of a preferred embodiment of the invention having reference to the accompanying drawings wherein:

FIG. 1 is an elevational view of the improved key in preferred actual size applied to a telescopic lock to be operated thereby, the lock being shown in central vertical section and in locked condition.

FIG. 2 is an enlarged fragmentary top plan view of the key drawn on an enlarged scale with portions of the key handles broken away.

FIG. 3 is a correspondingly enlarged view taken in section on the plane 3-3 in FIG. 2 looking in the direction of the arrows.

FIG. 4 shows a section on plane 4-4 in FIG. 3 looking in the direction of the arrows.

FIG. 5 shows a section on plane 5-5 in FIG. 3.

FIG. 6 shows a section on plane 6-6 in FIG. 3.

FIG. 7 shows a section on plane 7-7 in FIG. 3.

FIG. 8 shows a section on plane 8-8 in FIG. 3.

FIG. 9 is an enlarged View of the arable tongue of the key that makes clinging engagement with the plunger of the lock.

In FIG. l an unlocking key embodying the invention is adapted to be grasped maneuvered and operated by means of plier type handles 12, 13 and 14. The key has a composite lock engaging tongue comprising a tubular draw member 15 lfixed rigidly at one of its open ends to the jaw 13' of handle 13 and a core rod 16 slidable inside of member 15 having a portion of its length protruding from said open end of said member equipped with a spool-Shaped head 17 straddled and operably engaged by a forked jaw 12 of expander handle 12. The thickness of the tubular wall at the tip end of draw member 15 need not exceed .005.

Handle 1'2 is connected by a pivot pin 22 to the main or inter-mediate handle 13 so as to swing relatively thereto between its positions shown in full lines and broken lines in FIG. 3 for causing core rod 16 to slide lengthwise within and relatively to the tubular draw member 15. By thus sliding, a tapered end portion 23 of core rod 16 is drawn toward and into the thin walled terminal portion 24 of draw member 15. The internal surface of said wall forms a socket that tapers conically at an included angle that is less than the included angle of taper of rod end 23 and is castellated to about the depth designated (D) in FIG. 9 by slits 25 paralleling the axis of the key tongue and preferably three or more in number. It is preferred that the included angle not exceed ten degrees. Thus the hollow end portion 24 of draw member 15 can be eX- panded or flared radially in more than two lateral directions simultaneously to cause exceptionally strong frictional cling of the draw member of the key to a bolt controlling plunger in the lock which plunger as a whole is designated 31 in FIG. 1. The resulting expansive pressure of the draw member against the cylinder wall of the plunger will occur substantially around a complete circle. To better adapt the key t0 complete operation by the grasp of a single hand of the user a partially folded leaf spring 26 may have its ends anchored to handles 12 and 13 respectively as indicated in FIG. 1, the tension in spring 26 yieldably tending to spread the handles. In FIG. 1 typical separable parts adapted to be fastened together by the lock, or restricted to a limited degree of separation, are designated 63 and 64.

Lock 31 may be constructed as disclosed in U.S. Patent No. 3,002,368 and comprises two axially separable, telescopically assembled body sections such as the hollow main shank 32 with its enlarged head 33 and the tap 34 provided with at least one, and possibly two or more, internal annular grooves 35 and 36 within one or the other of which grooves the bolts of the lock, herein represented by hard balls 37, can seat and are held by the reduced end of the aforesaid plunger 30. The reduced portion 40 of plunger 30 extends within a counterbore 38 in the lower end of shank 32 and blocks the balls 37 from moving radially inward in transverse bores 39 in the wall of the shank within which bores the balls are shiftably retained. As the balls are thus held against shifting in bores 39 it follows that the balls are held secu-rely in place protruding partly within one or the other of the annular groove 35 or 36 so that cap 34 is held securely against removal from the main body shank 32.

When the plunger is shifted upward in FIG. 1 by the draw member 15 of the key to the point where portion 40 clears the balls 37, the latter are free to retract radially inward of the body shank 32 to a sufficient extent to permit the balls to become entirely clear of cap 34, whereupon the latter may easily be removed from body shank 32 to open the lock.

The plunger 3) is formed with an integral annular shoulder 41 which, by abutment with an annular ledge 42 in the body shank 32, limits the downward movement of the plunger 30 to its locking position indicated in FIG. 1. The plunger is normally held yieldably downward in such locking position by a coil spring 43 which encompasses an upper extension 44 of the plunger, both plunger and spring -being movably disposed within the main bore 45 in body shank 32. Spring 43 is compressed between the upper surface of the shoulder 41 and an undersurface 46 of a plug 47 which is removably fixed in an enlarged counterbore in the shank head 33. Plug 47 affords a slide bearing for the draw member 15 of the key. The top end of plunger 30 is free to enter bore 62.

A third handle 14, which herein will be termed the draw handle, is connected by pivot pin 54 to the main or intermediate handle 13 so as to swing relatively thereto between its positions shown in full lines and in broken lines in FIG. 3 for causing draw member 15 to be pulled outward of the lock while maintained in frictional clinging engagement with the plunger 30 of the lock. A conventional handle spreading spring 56 whose ends are anchored respectively to handles 13 and 14 is tensioned to yieldably urge handles 13 and 14 apart. Force multiplying leverage results when handles 13 and 14 are squeezed together in the palm of the user of the key because the jaw 14 of handle 14 will be rested against the end of the lock body as shown in FIG. l which latter serves as a fulcruni against which handle jaw 13' can rock as it is being separated from jaw 14' of handle 14 by the squeezing together of handles 13 and 14. Jaw 14 contains an aperture 55 elongated lengthwise of the jaw which accommodates the relative swinging movement that takes place between draw member 15 and jaw 14. It will be apparent that during this upward drawing of lock plunger 30 the strong frictional cling of draw member 15 to the plunger 30 will be positively maintained if the expander handle 12 is included with handles 13 and 14 in the handle squeezing grasp of the user because lhandle 12 will then remain urged to swing toward handle 13 at the same time that handle 13 is closed toward handle 14. Spacer washers 57 centralize handles 12 and 13.

What is claimed is:

1. A key of the pliers type for opening a tamper foiling lock controlled by a hollow reciprocative plunger comprising, a tubular draw member adapted to be inserted in the plunger of the lock, an expander comprising a core rod `reciprocable lengthwise inside of and relatively to said draw member in a manner to expand said member into clinging engagement with the plunger of the lock for reciprocating said plunger, and two plier type handles pivotally coupled together to be swingable about a common pivotal axis and shaped and arranged to be held and swung relatively by a single hand of the operator, said member and rod being connected to said two handles in a manner to be caused to perform relative reciprocative in an axial direction, responsively to relative swinging movements of said handles.

2. A key of the pliers type as defined by in claim 1, in which the said draw member is carrier by one of the said two handles in rigid relation thereto, together with a third handle pivotally connected to said one of said two handles containing an aperture through which said draw member extends.

3. A key of the pliers type as defined in claim 2, in which the said aperture is elongated lengthwise of the said third handle to accommodate swinging movement of the said draw member in unison with the swinging movement of the said one of said two handles.

4. A key of the pliers type as defined in claim 2, together with a spring under compression between and tending to spread the said third handle and the said one of the said two handles, and a separate spring under tension between and tending to spread said one of said two handles and the other of said two handles.

5. A key of the pliers type as defined in claim 2, in which the said common pivotal axis of two of said handles is located at a 4point between the said core rod and the point of pivotal coupling together if said third handle to said one of said two handles.

6. A key of the pliers type as defined in claim 5, in which the said core rod has a spool-shaped head, and the other of said two handles has a forked jaw straddling said head.

References Cited UNITED STATES PATENTS 297,658 4/1884 Bacon or a1 29-267x 478,009 6/1892 Honig 81-4119 x 1,058,454 4/1913 Moores s1 72 x 1,363,934 12/1920 Upton 29-280 1,851,421 3/1932 Cookin-1 81-72 2,159,655 5/1939 Do Mooy 29-268 x 2,814,098 11/1957 Kossou 29*267 3,033,016 5/1962 Morug 70-395 3,052,973 9/1962 wiinams 29-282 x MARVIN A. CHAMPION, Primary Examiner.

P. TEITELBAUM, Assistant Examiner. 

